Note these numbers are for uncompressed data, just to give you
an idea on raw data throughput. With compressible data,
throughput can go up by a factor of 2 or 3 over these ratings.
However, because graphic images on web pages are already
compressed, the real multiplier for web browsing generally works
out to around 1.5 to 2x the above listed rates. So divide the
times by 2 to approximate real world download times assumming 2
to 1 compression. Faster is better! It is easy to cost justify
that $100 for a 56K modem if you value your time. Amazing but
true, a large number of web surfers out there still use those
tired 14.4 modems.

Life is short. Get a
V.90 modem fast!

Two rows of data are shown for V.90 modems because your
connect speed will vary depending on the quality of your phone
line and distance to your "CO" or Central
Office (local telephone facility). A pretty good line should
get about a 48 to 50K connection. The Telephone
Network was designed to carry voice traffic, not the flood of
data transfer it is being used for today. It is generally claimed
that people who live within 3 1/2 miles from their central office
will get significantly better connect speeds using a V.90 modem
over using a V.34 modem.

DTE vs DCE speed. Modem shoppers in stores
like CompUSA often ask why they should buy a 56K modem, when
their modem already says "connected at 57600" or
"connected at 115200". Well, this is a common
misunderstanding of what the reported connect speed means. These
speeds are the DTE (Data Terminal Equipment) speed, which is the
speed of the connection between your PC and your modem. The DCE
(Data Communications Equipment) speed is the bottleneck. The DCE
speed is the speed between your modem and the other modem you
connect to. Prior to 56K modems, the best speed you could get
between two modems was 33600 bits per second. Now using 56K
technology, rates approaching 50000 bits per second are
achievable.

Asymetric Data. Notable is that the V.90
standard calls for 'asymetric' data rates, just as both K56flex
and X2 did before the standard. This means that the send and
receive data speeds are different when you connect in V.90 mode.
Fortunately, high speed (up to 54Kbps) is realized in the
downstream direction, which is good since this is where the bulk
of the data is, downloading graphics, etc. from the internet to
your modem. The upstream direction is limited to 33.6Kbps, which
is OK, since most of the data web surfers send is mouse click
commands, which don't require much data to be transmitted.